Japanese Journal of Applied Physics

High Tc Superconducting Flash A/D Converter Using Planar Quasi-One Junction Superconducting Quantum Interference Devices (SQUIDs)

Toshimasa Umezawa, T. Fujita, Yasushi Higashino

Published Aug 1, 1996• 1 citation

Abstract

We have designed and fabricated a planar HTS (DyBaCuO) superconducting quasi-one junction (QOS) Superconducting Quantum Interference Device (SQUID) for a flash A/D converter using step-edge Josephson junctions. The simulation suggests that the HTS QOS bandwidth is limited with 2.6 GHz by an external shunted capacitor. To fabricate a 1–2 µ m size SQUID inductance hole and step-edge junctions, a stepper photo-lithography process was employed. To make a sensitive comparator, a flux transformer was directly installed on the QOS, whose magnetic field gain of 833 was in agreement with the designed value of 828. The basic analog to digital conversion test of the QOS comparator was confirmed at a frequency of 10 kHz–1 MHz at 77 K. The dynamic range was estimated as 2Φ0.

DOI: 10.1143/jjap.35.l981

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